gnu: libtasn1: Add replacement to fix CVE-2017-10790.

Based on commit 01a61d7040b1794f36547b107abce6e967d59f21
by Leo Famulari <leo@famulari.name>.

* gnu/packages/patches/libtasn1-CVE-2017-10790.patch: New file.
* gnu/local.mk (dist_patch_DATA): Add it.
* gnu/packages/tls.scm (libtasn1)[replacement]: New field.
(libtasn1/fixed): New variable.

2 files changed, 72 insertions, 1 deletions

diff --git a/gnu/packages/patches/libtasn1-CVE-2017-10790.patch b/gnu/packages/patches/libtasn1-CVE-2017-10790.patch
new file mode 100644
index 0000000000..6cec0c8030
--- /dev/null
+++ b/gnu/packages/patches/libtasn1-CVE-2017-10790.patch
@@ -0,0 +1,63 @@
+Fix CVE-2017-10790:
+
+https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-10790
+
+Patch copied from upstream source repository:
+
+https://git.savannah.nongnu.org/cgit/libtasn1.git/commit/?id=d8d805e1f2e6799bb2dff4871a8598dc83088a39
+
+From d8d805e1f2e6799bb2dff4871a8598dc83088a39 Mon Sep 17 00:00:00 2001
+From: Nikos Mavrogiannopoulos <nmav@redhat.com>
+Date: Thu, 22 Jun 2017 16:31:37 +0200
+Subject: [PATCH] _asn1_check_identifier: safer access to values read
+
+Signed-off-by: Nikos Mavrogiannopoulos <nmav@redhat.com>
+---
+ lib/parser_aux.c | 17 ++++++++++++-----
+ 1 file changed, 12 insertions(+), 5 deletions(-)
+
+diff --git a/lib/parser_aux.c b/lib/parser_aux.c
+index 976ab38..786ea64 100644
+--- a/lib/parser_aux.c
++++ b/lib/parser_aux.c
+@@ -955,7 +955,7 @@ _asn1_check_identifier (asn1_node node)
+ 	  if (p2 == NULL)
+ 	    {
+ 	      if (p->value)
+-		_asn1_strcpy (_asn1_identifierMissing, p->value);
++		_asn1_str_cpy (_asn1_identifierMissing, sizeof(_asn1_identifierMissing), (char*)p->value);
+ 	      else
+ 		_asn1_strcpy (_asn1_identifierMissing, "(null)");
+ 	      return ASN1_IDENTIFIER_NOT_FOUND;
+@@ -968,9 +968,15 @@ _asn1_check_identifier (asn1_node node)
+ 	  if (p2 && (type_field (p2->type) == ASN1_ETYPE_DEFAULT))
+ 	    {
+ 	      _asn1_str_cpy (name2, sizeof (name2), node->name);
+-	      _asn1_str_cat (name2, sizeof (name2), ".");
+-	      _asn1_str_cat (name2, sizeof (name2), (char *) p2->value);
+-	      _asn1_strcpy (_asn1_identifierMissing, p2->value);
++	      if (p2->value)
++	        {
++	          _asn1_str_cat (name2, sizeof (name2), ".");
++	          _asn1_str_cat (name2, sizeof (name2), (char *) p2->value);
++	          _asn1_str_cpy (_asn1_identifierMissing, sizeof(_asn1_identifierMissing), (char*)p2->value);
++	        }
++	      else
++		_asn1_strcpy (_asn1_identifierMissing, "(null)");
++
+ 	      p2 = asn1_find_node (node, name2);
+ 	      if (!p2 || (type_field (p2->type) != ASN1_ETYPE_OBJECT_ID) ||
+ 		  !(p2->type & CONST_ASSIGN))
+@@ -990,7 +996,8 @@ _asn1_check_identifier (asn1_node node)
+ 		  _asn1_str_cpy (name2, sizeof (name2), node->name);
+ 		  _asn1_str_cat (name2, sizeof (name2), ".");
+ 		  _asn1_str_cat (name2, sizeof (name2), (char *) p2->value);
+-		  _asn1_strcpy (_asn1_identifierMissing, p2->value);
++		  _asn1_str_cpy (_asn1_identifierMissing, sizeof(_asn1_identifierMissing), (char*)p2->value);
++
+ 		  p2 = asn1_find_node (node, name2);
+ 		  if (!p2 || (type_field (p2->type) != ASN1_ETYPE_OBJECT_ID)
+ 		      || !(p2->type & CONST_ASSIGN))
+-- 
+2.13.3
+
diff --git a/gnu/packages/tls.scm b/gnu/packages/tls.scm
index 5a94ac6198..7ee341e99b 100644
--- a/gnu/packages/tls.scm
+++ b/gnu/packages/tls.scm
@@ -1,6 +1,6 @@
 ;;; GNU Guix --- Functional package management for GNU
 ;;; Copyright © 2012, 2013, 2014, 2015, 2016, 2017 Ludovic Courtès <ludo@gnu.org>
-;;; Copyright © 2014, 2015, 2016 Mark H Weaver <mhw@netris.org>
+;;; Copyright © 2014, 2015, 2016, 2017 Mark H Weaver <mhw@netris.org>
 ;;; Copyright © 2014 Ian Denhardt <ian@zenhack.net>
 ;;; Copyright © 2013, 2015 Andreas Enge <andreas@enge.fr>
 ;;; Copyright © 2015 David Thompson <davet@gnu.org>
@@ -55,6 +55,7 @@
   (package
     (name "libtasn1")
     (version "4.12")
+    (replacement libtasn1/fixed)
     (source
      (origin
       (method url-fetch)
@@ -74,6 +75,13 @@ networking, allowing for formal validation of data according to some
 specifications.")
     (license license:lgpl2.0+)))
 
+(define libtasn1/fixed
+  (package
+    (inherit libtasn1)
+    (source (origin
+              (inherit (package-source libtasn1))
+              (patches (search-patches "libtasn1-CVE-2017-10790.patch"))))))
+
 (define-public asn1c
   (package
     (name "asn1c")